116 PROCEEDINGS OF THE ACADEMY OF [1889. 



They form a layer much thicker than that formed by the ordinary 

 endodermal cells, and are loaded with green granules, closely packed 

 together so that to the naked eye the region occupied by this layer 

 is of that color. Foreign bodies of organic nature are imbedded in 

 the cells, sometimes being surrounded by a number of cells contain- 

 ing no granules, or occasionally imbedded in the mesogloea. 



In unstained specimens, when the animal is laid open by a lon- 

 gitudinal incision, this region of the mesenteries is very distinct 

 on account of its rich preen color. When the loose cells of the 

 green area are scraped away with a scalpel and examined, they are 

 seen to be of a very irregular shape (suggesting a power of amoeboid 

 movement), and to contain numerous green globules, much smaller 

 than the zooxanthellre, darker in color, and homogeneous in struct- 

 ure. Amongst the cells are numerous zooxanthellse, and there are 

 also numerous spherical refractive bodies, apparently of a fatty 

 nature and with a slightly-greenish tinge, as well as the foreign 

 bodies already mentioned as seen in the section, and very numerous 

 delicate acicular silicious spicules. 



The occurrence of these spicules and organic foreign bodies in the 

 cells of this region is very strong evidence in favor of the supposi- 

 tion that they have a digestive function. The green globules may 

 be the products of digestion. If this be the case it is exceedingly 

 interesting as indicating a method of digestion in the Zoanthea? 

 somewhat different from what is usually described as occurring in the 

 rest of the Actiniaria. 



None of the specimens examined possessed sexual organs. There 

 were about 24-26 pairs of mesenteries in the specimens examined. 



I have identified this form with Duchassaing and Michelotti's 

 Z. flos-marinm, with the imperfect description of which it agrees 

 fairly well. In many respects it comes near Z. sociatus, but differs 

 markedly from it in others ; such for instance as in the nature of the 

 ectoderm and in the form of the sphincter-muscle, so that it must be 

 regarded as distinct. From the only Zoanthus hitherto described 

 from the Bermudas, Z. Dance (?) of Hertwig 1 it is readily dis- 

 tinguished by the absence of any distinct line of demarcation be- 

 tween the upper and lower portions of the column. 



1 K. Hertwig. Supplement to report on the Actiniaria of the Challenger 

 Expedition. 188S. 



